1. Summary of the Invention
This invention generally relates to aligning the blades and fletching of an arrow and, more particularly, to an arrow provided with an improved coupling assembly between its shaft with fletching and its broadhead with blades to adjust the rotational orientation therebetween so as to axially align the broadhead and fletching for optimizing the aerodynamic characteristics of the arrow.
2. Summary of the Background Art
The flight of an arrow may be adversely affected by a wide variety of factors, internal and external. Adverse external factors include environmental conditions, particularly the wind. Adverse internal factors include excessive drag during flight, rotational non-symmetry and the like. These internal factors may be aggravated with the use of hunting arrows employing broadheads.
A broadhead is that portion of a hunting arrow located at the forward or tip end. It includes individual blades, normally interchangable, and an arrangement for its removable coupling with the shaft. Broadheads are removably coupled to the forward end of a shaft in order to provide the user with the ability to select an appropriate broadhead matched with the intended game. Such removability also allows the user to uncouple a shaft from a broadhead which has become irretrievably imbedded in a tree or other surface and to provide the forward end of such shaft with a new broadhead. Blade interchangability allows the user to replace a damaged blade or blades of a broadhead. The interchanging of blades normally involves the uncoupling of broadhead and shaft. The uncoupling and recoupling of broadhead and shaft is, therefore, not uncommon.
The coupling and uncoupling of a broadhead and shaft always carries with it the possibility of introducing misalignment into the arrow between the blades and fletching. Any misalignment within an arrow will cause its flight to be aerodynamically deficient because of drag or rotational wabble. Proper alignment within an arrow will improve its internal factors and also make it less affected by external factors such as the wind.
One prior technique for rotationally adjusting broadheads and shafts was in common usage when they were coupled by an adhesive. According to that technique, the rearward end of the broadhead included a male coupling cylinder which was received within a mating female cylindrical opening at the forward end of the shaft. Included therebetween was an adhesive, softenable under heat, which could allow for the desired rotational alignment. Such a technique, however, was time consuming and somewhat inconvenient since it required heat which was not always available, particularly since a user might wish to change broadheads in the field. Additionally, shafts and broadheads are now more often coupled with newer, stronger adhesives which are epoxy based. Such newer adhesives are not softenable upon the application of heat so that this rotational adjustment technique is no longer available.
Arrows should thus be designed for the uncoupling and recoupling of broadhead and shaft in such a way as to allow for the convenient rotational adjustment between broadhead and shaft to thereby axially align the blades of the broadhead with the fletching of the shaft.
The patent literature shows that this design objective is well recognized. It does not, however, provide any solution which is sufficiently efficient, convenient, reliable and economical. Consider, for example, U.S. Pat. No. 4,210,330 to Kosbab. According to that disclosure, a resilient washer of rubber, plastic or the like is positioned between the broadhead and shaft. Tightening or loosening of such rotational elements may thus bring the rotational elements into proper alignment through the compressing or relaxing of the washer. Unfortunately, the elastic limit of the washer will limit the degree of rotational adjustment available which may or may not provide sufficient adjustment capabilities for a particular application. Further, the elastic limit of the washer will vary through age and use. Beyond this, the tightening will induce a bulge in the washer and detract from the aerodynamic properties of the arrow.
U.S. Pat. No. 4,036,499 discloses an improved arrangement for releasably coupling a broadhead and shaft. This arrangement includes a one piece cylindrical member threaded at both ends for releasably coupling a broadhead and shaft. An intermediate collet formed integrally with the cylindrical member limits the axial movement of the broadhead and shaft with respect to the cylindrical member. This constitutes a convenient arrangement for releasably coupling the parts of an arrow but provides for no adjustment capabilities normally desired by users of arrows.
As illustrated by the large number of prior patents as well as commercial devices, efforts are continuously being made in an attempt to adjustably couple arrow broadheads and shafts more efficiently, conveniently, reliably and economically. None of these previous efforts, however, provide the benefits attendant with the present invention. Additionally, prior techniques and apparatus do not suggest the present inventive combination of component elements arranged and configured as disclosed and claimed herein. The present invention achieves its intended purposes, objectives and advantages over the prior art devices through a new, useful and unobvious combination of component elements which is simple to use, with the utilization of a minimum number of functioning parts, at a negligible cost to manufacture and by employing only readily available materials.
Therefore, it is an object of this invention to provide an improved arrow having a shaft with fletching, a broadhead with blades and a coupling assembly therebetween to adjust the rotational orientation between the shaft and broadhead so as to axially align the fletching and blades for optimizing the aerodynamic characteristics of the arrow.
It is a further object of this invention to provide an improved coupling assembly between a shaft with fletching and a broadhead with blades for adjusting the rotational orientation between the shaft and broadhead so as to axially align the fletching and blades.
It is an additional object of the invention to adjust the rotational orientation between the broadhead and the shaft of an arrow.
Lastly, it is an object of the invention to axially align the blades and fletching of an arrow.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiments in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.